Male infertility Flashcards
Azoospermia incidence and causes
1% male population
10% of those with male infertility have azoospermia
36% obstructive azoospermia
60% non-obstructive azoospermia
3% hypogonadotrophic hypogonadism
Pretesticular - amenable to medication intervention
Genetics of azoospermia
NOA - 73% unknown. TEX11 (meiotic germ cell arrest). AZF microdeletions. Karyotype anomalies - 47XXY, 46XX male syndrome
CBAVD - CFTR gene mutation, ADGRG2, 10% unknown
Hypogonadotrophic hypogonadism - 50% idiopathic 50% genetic - i.e. ANOS1, SOX10, SOX2, GNRHR gene defect.
Investigations for OA
Targeted investigations
Diagnosis of obstructive azoospermia
Low volume and acidic semen pH suspicious for OA.
Retrograde ejaculation
Diminished volume or complete lack of seminal emission.
Often first symptoms of diabetes mellitus.
Diagnosed by microscopic examination of postejaculation urine.
Pseudoephedrine (Sudafed) 120mg tds ~25% will achieve antegrade ejaculation.
Ejaculation with a full bladder is sometimes helpful.
Urine can be alkalinised and the sperm from the postejaculate urine retrieved, processed and used for IUI, IVF or ICSI
CBAVD
1 in 1000 males
Assoc with seminal vesicle agenesis in 50% of cases, renal agenesis (unilateral) in 5-10%
Prevalence of CBAVD in azoospermic men - 5-15%. 25% of cases of OA.
CBAVD with SV agenesis = azoospermia, low semen volume and pH <7
F508 and 5t alleles highest risk of CBAVD
ADGRG2
Adhesion G protein couples receptor G2, critical regulator of male fertility, maintains pH homeostasis.
Found of X chromosome (Xp22.13)
Found in 10-20% of CBAVD patients with negative CFTR gene mutations.
Should be assayed if renal USS is normal.
Genetic counselling recommended.
?PGT-A and transfer male patients only.
Investigations for NOA
If normal volume azoospermia.
Step one is to centrifuge sample to identify if cryptozoospermia (virtually no sperm) - may be able to retrieve enough from this to freeze for ICSI
FSH and testicular volume can be effective at predicting diagnosis.
High FSH >7.6IU/L and low testicular volume <4.6cm= NOA 96% accuracy
Low FSH <7.6IU/L and normal testicular volume >4.6cm = OA 89% accuracy
Sperm concentration to ask for karyotype.
<5million/ml.
If KS suspected always ask for 100cells to be tested for mosaicism.
Predictive factors of SR in micro-TESE
FSH level, T levels, Testicular volume are all POOR predictors - AUC 0.52-0.59
AZF microdeletions - A (Awful) no sperm. B (bad) 5% chance of sperm C (chance) 45% SRR.
Histology best predictor but not recommended as may disrupt one area of spermatogenesis.
-hypospermatogenesis - 75-100% SRR
- Sertoli only syndrome - 22-40% SRR
- Maturation arrest - 30-80% SRR
- Seminiferous tubule hyalinisation - 14-48% SRR
TESE versus micro-TESE
Conventional TESE
- blind approach
- failure to retrieve sperm
- Devascular injury
- massive tissue loss
- decrease in testicular function
SR - MicroTESE 1.5 higher SRR than conventionalTESE (2015)
Klinefelter syndrome - incidence and impact on fertility
47XXY
Most common genetic abnormality in men (1 in 650) 50% never diagnosed.
14% of patient with azoospermia have Klinefelters
10-15% will be mosaic klinefelters (more likely to find sperm)
Phenotype of KS and causes of variable phenotypes in Klinefelters
Varying degrees of hypogonadism
CAG repeat polymorphisms (androgen receptor repeats)
Mosaicism
X chromosome inactivation
Origin of extra X chromosome
Pseudo-autosomal region gene activty
Epigenetics
Mechanism of Testicular dysfunction in KS
Consequence of progressive germ cell degeneration
Extensive fibrosis and hyalinisation of semniiferous tubules
Hyperplasia of interstitum and Leydig cells
Likely all driven by increased apoptosis.
Fertility options for KS
- Ejaculated sperm (8%)
- Sperm banking
- Micro-TESE (gold standard)
- Donor sperm
- Donor embryo
- Adoption
- stem cell therapy (experimental and in infancy)
KS pre microTESE preparation and outcomes
3-6months of anastrazole is generally prescribed if azoospermia confirmed on SA before SSR attempted.
Need to be off T for 6-9months at least
repeat microTESE not recommended.
cTESE - 42%
MicroTESE - 57%
LBR 29-43%
in KS for some reason the sperm only have the haploid chromosome number - vast majority is X or Y only.
ROSI
round spermatid injection (in men with azoospermia)
Very poor outcomes - 39% fertilised but only 4% live birth per embryo transferred
Sperm DNA frag
Caused by oxidative stress and ROS causing breaks in DNA (single or double stranded).
Need a small amount of DNA frag to help with capacitation, fertilisation, embryo development.
However too much not good, if oxidative stress is too high compared to anti-oxidants.
Sperm vulnerable as minimal cytoplasm with low antioxidant load, high proportion of highly unsaturated fatty acids - causes release of free radicals,
May be associated with:
Poor embryo development – particularly from cleavage stage to blastocyst development
RPL
Unexplained infertility
Repeated IVF failures
RIF – conflicting (not recommended to test for this in RIF by ESHRE)
Sperm DNA fragmentation tests
TUNEL (GS) and COMET - direct identification of damage through enzymatic reactions and fluoroscence miscroscopy. DNA frag index result.
SCSA and SCD Sperm chromatin dispersion) - indirect test, DNA susceptible to degeneration by acid (halo around is the normal result in SCD, green stain normal in SCSA)
All have problems with lack of standardised protocols, inter-observer variability and no RCTs done
Measuring DNA frag and Clinical outcomes of MAR: A SR and MA
2016
Current test have limited capacity to predict the chance of pregnancy in the context of MAR. Furthermore, DNA frag tests have little or no difference in predictive value between IVF and ICSI
MOXI trial (2020)
effect of antioxidants on MFI, RCT. Fert ster 2020. SS 147.
No improvement in semen parameters or DNA integrity among men with MFI. Limited by sample size, but suggests don’t improve in vivo pregnancy or live birth rates.
Role of sperm DNA frag testing in predicting IUI outcome - a SR and MA
2019
DNA frag index can’t predict IUI outcome or in advising for or against IUI
Indications for testing for sperm DNA frag
Erectile dysfunction
Lifestyle modifications - exercise, diet, stop smoking, stop drugs, reduce ETOH
Control risk factors - obesity, hypertension, dyslipidaemia, diabetes
Psychosexual counselling - if psychological cause
Medications - phosphodiesterase-5-inhibitors (PDE-5 inhibitors)
Phosphodiesterase 5 inhibitors for ED (PDE-5 inhibitors)
Phosphodiesterase 5 inhibitor – inhibits the degradation of cGMP which is the molecule that causes efflux of calcium and therefore maintains smooth muscle relaxation and increases blood flow into the penis.
sildenafil (viagra) - 50mg tablet once off, one hour before, effective for 4 hours
Tadalafil (cialis) - 10mg - 30mins, works up to 36hours post dose
Premature ejaculation
SSRI - dapoxetine (short half life, rapid onset and offset, minimal side effects, need to take 3 hours before intercourse) can be used with PDE5 inhibitor)
parozetine -need to take daily rather than on demand, improves latency after a few days, max effect achieved after 1-2weeks)
Retrograde ejaculations